1. Field of the Invention
The invention relates to and has among its objects the provision of novel processes for peeling fruits and vegetables. Further objects of the invention will be evident from the following description wherein parts and percentages are by weight unless otherwise specified.
2. Description of the Prior Art
In conventional practice in food processing plants, many fruits and vegetables are peeled by dipping them in hot lye (NaOH) solution, and then removing the loosened skin by wiping with rotating, soft rubber discs, or by flushing with jets of water. Although such lye-peelng procedure is effective, it presents several disadvantages. In the first place, high peeling losses occur because the caustic removes a substantial proportion of the softer tissue in the flesh of the fruit or vegetable as well as the peel. It is evident that high peeling losses are economically undesirable. Also, the peeled products do not have an attractive appearance because of removal of some of the flesh. This is, of course, a disadvantage where the product is intended for canning in the whole state. Another disadvantage of lye-peeling is that it yields a waste having a high NaOH content so that it is difficult to dispose of; many communities require that the waste be neutralized prior to releasing it into sewage plants, and even such neutralization, which is a considerable expense, does not alter the detrimental effect of its high sodium content.
To increase peeling efficiency in the lye-peeling method, various surfactants are added to the caustic peeling solution. For example, minor amounts of sodium 2-ethylhexylsulfate, sodium mono- and dinaphthalene sulfonates, or certain aliphatic acids have been used in conjunction with lye to peel fruits and vegetables. However, although peeling efficiency is increased, the use of caustic solutions containing surfactants is still subject to the same disadvantages as outlined above for caustic alone.
Peeling of fruits and vegetables is also accomplished using hot water, steam, or simple abrasion. These methods also have the disadvantage of high peeling losses, i.e., loss of valuable flesh, and uneven peeling.